Telegraph.



o. 781,752. PATBNTED FEB. 7, 1905.

F. A. STUMM. TELEGRAPH.

APPLICATION FILED DBGA, 1902.

WITNESSES. INVENTOR A fro/717E rs.

UNITED STATES Patented February '7, 1905.

FRANK ALBERT STUMM, 0F NETV YORK, N. Y.

TELEGRAPH.

SPECIFICATION forming part of Letters Patent No. 781,752, dated February '7, 1905.

Application filed December 4, 1902. Serial No. 133,883.

To I /Z whom it 'ntrt l concern.-

Be it known that I, FRANK ALBERT S'IUMM, a citizen of the United States, and a resident of the city of New York, borough of Manhattan, in the county and State of New York, have invented a new and Improved Telegraph, of which the following is a full, clear, and exact description.

My invention relates to telegraphy, and more particularly to provision against the disturbing eli'ects due towet weather upon lines using the duplex, quadruplex, and other sys tems in which the line is required to be kept approximately in balance.

My invention rests upon the discovery that by inserting a suitable artificial resistance in the main-line circuit between the relay and the line-wire proper the working of the line is greatly improvcd-so' much so that the capacity for transmitting messages may be greatly increased above what it would otherwise be in wet weather.

It may be remarked that in telegraphic sys tems of the kind above mentioned the resistance of theline must be kept in balance, which is done by interposinga variable resistance in the so-called equating-circuit-that is to say, in every such system it is necessary to vary the resistance of the equating-circuit in order to bring the lines into balance in all cases where the main-line wire is subject to leakage or analogous disturbing causes.

Reference is to be had to the accompanying drawing, forming a part of this specification, in which the figure is a diagrammatic representation of my system as applied to an ordinary duplex telegraph.

The main-line wire is shown at 1. At each end of the line-wire are disposed variable resistances consisting of switches 2 3, which may be moved by hand at will over the rheostatic connections a 5. Polarized relays 6 T of the usual pattern are provided with oppositely-wound poles 8 9. A wire 10 from one of the poles 9 is connected with the resistance 11, controllable by means of a handswitch 12, this switch being connected by a wire 13 with the wire 15, which leads to the normal contact H and to the ground-wire 16.

Branch wires 17 18 are connected with the wire 19. which leads to the key 20, this key being provided with an abnormal contact .21 in the usual manner. The line may be energized by a battery 2:2 and is groundei'l at 23. At the other end of the line the arrangement is similar, the wire Z-L being connected with the resistance 25, controllable by the switcharm 26, this switch-arm being connected by wires 27 and 29 with the normal contact 28 and with the ground-wire 30. Branch wires 31 32 are connected with the relay '7 and with the wire which leads to the key 3- this key having an abnormal contact 35 connected directly with the ground-wire 30. A battery 36 is inserted in the circuit at this end of the line. This battery is inserted in the wire 30, which is grounded at 37. If desired, dynamos 38 39, provided with cut-out switches a0 11, may be employed instead of the batteries 22 and 36. For this purpose cut-out switches a2 and 43 are provided, so as to throw the batteries out of circuit when the dynamos are to be used.

My invention is used as follows: Suppose, for instance, that the normal resistance of the main line in dry weather is two thousand ohms and that because of wet weather the ohmic resistance of the main line is dropped to a certain unknown degree. The operators by means of the hand-switches 12 or 26 adjust the resistances 11 or 25 to such a point that the line balances. in other words, as in ordinary systems, each operator brings the line to a balance by varying the resistance of the socalled equating-circuit and notes the change in resistance necessary to accomplish this result. Say, for instance, that the resistance of the main line is found to be one thousand ohms instead of the normal resistance of two thousand ohms above mentioned. The falling oil in the resistance is clearly one thousand ohms. The operator next adjusts one of the hand-switches 2 or 3, so as to cut into the main line a resistance equal to, say, fifty per cent. of the ditl'erence just ascertained. He therefore cuts in tive hundred ohms. Each operator now moves his handswitch 12 or 26 and again balances the line.

Of course the resistance of the line is now greater than before, and when the line is thus balanced for the second time it is ready for use and the operation of telegraphy may proceed. Of course the hand-switches 2 or 3 are moved to the Zero-point when the first balance is taken and are at some other point when the second balance is taken. The principle appears to be that by the introduction of the rheostatic members 4: and 5 the current passing through the main line is less subject to fluctuations or disturbances than would be the case if no such resistances were introduced. In other words, with a considerable current flowing through the main line and resistances connected therewith the variations are not nearly so noticeable, and the effect is practically the same as if the points of leakage were moved farther away from the relay, so that their effect is not so marked.

While the degree of resistance which I prefer to introduce into the main-line resistances is fifty per cent. of that found by a difference between the normal main-line resistance and the resistance during wet weather and is found by balancing the line by means of the equating-circuit, yet this particular proportion is in a sense arbitrary, and I do not, therefore, limit myself to any particular percentage. I have found from experience that fifty per cent. gives a very satisfactory result.

The adjustment of the line under my system may therefore be summarized as follows: First, balance the line by means of the equating-circuit and find the loss in resistance of the main line; second, add to the main line an artificial resistance representing. one-half of that thus ascertained; third, let this resistance stay in the main line and balance the main line by means of the equating-circuit. The line is then ready to be used.

The operation of the system is practically the same whether dynamos or batteries are used; butallowance should be made for the fact that with dynamos the internal resistance is practically nothing; but with batteries the internal or cell resistance may be very great.

It will be understood, of course, that the equating-circuit mentioned herein is either the one consisting of the wire 10, rheostatic mem ber 11, wire 13, and ground or the one consisting of wire 2%, rheostatic member 25, wire 27, and ground.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. The method, herein described, of ameliorating current fluctuations in balanced lines used for purposes of communication, which consists in determining the mean variation of the main circuit from a predetermined normal, increasing the resistance of the main-line circuit to an extent proportionate to the Variation thus determined, and balancing the mainline circuit with its resistance thusincreased.

2. The method, herein described, of ameliorating current fluctuations in balanced lines used for purposes of communication, which consists in taking a balance of the mainline circuit, thereby determining the mean variation in the current thereof from a predetermined normal, increasing the resistance of the mainline circuit to an extent proportionate to the mean variation thus determined, and again balancing the main circuit with its resistance thus increased.

3. The method herein described of ameliorating current fluctuations in balanced lines used for purposes of communication, which consists in determining the mean variation of the current of the mainline circuit from a predetermined normal, changing the resistance of the main-line circuit to the extent of approximately fifty per cent. of the variation thus determined, and then balancing the main-line circuit.

L. The method herein described of ameliorating current fluctuations in balanced lines used for purposes of communication, which consists in taking a balance of the mainline circuit, changing the resistance of the mainline circuit and taking a second balance of said mainline circuit.

5. The method herein described of ameliorating current losses in balanced lines used for purposes of communication, which consists in balancing the line, thereby determining the main variation of the resistance of the mainline circuit below a predetermined normal, adding to the resistance of the mainline circuit a resistance equal to approximately fifty per cent. of the loss thus ascertained, and finally taking a new balance of the mainline circuit.

6. The method herein described of ameliorating current fluctuations in balanced lines used for purposes of communication, which consists in ascertaining the normal resistance of the main-line circuit, balancing the line to detect and determine any lossin the observed resistance of said main-line circuit as compared with the normal resistance thereof, adding to said observed resistance of said mainline circuit a resistance approximating one-half of the loss in the resistance thus ascertained, and finally balancing said main-line circuit including said resistance thus added thereto.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

FRANK ALBERT STUMM.

\Vitnesses:

RICHARD N. CoTTER, A. H. LOWERN, Jr. 

